Battery: A device that produces electricity to provide power for radios, cars, etc.
Noun. I left my car lights on all night and now the battery is flat.
Compass: A device for finding direction with a needle that can move easily and that always points to magnetic north.
Noun. The only tools for the copying that we can see are a pair of compasses.
Candle: A stick-shaped piece of wax with a wick (= piece of string) in the middle of it that produces light as it slowly burns.
Noun. Shall I light a candle?